Temperature dependence of the epidermal growth factor receptor signaling network can be accounted for by a kinetic model
Temperature dependence of the epidermal growth factor receptor signaling network can be accounted for by a kinetic model
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DOI：
10.1021/bi011506c
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发表时间：
2002-01-08
期刊：
影响因子：
2.9
通讯作者：
Kholodenko, BN
中科院分区：
文献类型：
--
作者：
Moehren, G;Markevich, N;Kholodenko, BN
用表皮生长因子（EGF）刺激分离的肝细胞导致EGF受体（EGFR）和衔接子/靶蛋白的快速酪氨酸磷酸化，在37、20和4 ℃下以1和2 s分辨率监测。检测到的多个信号蛋白的时间响应涉及瞬时和持续的磷酸化模式，在低温下发生显着变化。为了定量解释复杂的反应，我们采用了EGFR途径的机械动力学模型，从分子角度将其表述为蛋白质相互作用以及磷酸化和去磷酸化反应的级联。假设不同的温度依赖性不同的反应组，如SH 2和PTB结构域介导的相互作用，EGFR激酶，和磷酸酶，计算机模拟和测量的反应之间获得了良好的定量协议。动力学模型表明，对于每个蛋白质-蛋白质相互作用，解离速率常数。k（off）在低温下强烈降低，而这种降低可能伴随或可能不伴随k（on）值的大幅降低。温度诱导的变化，由EGFR激酶催化的反应的最大活动是温和的，相比，这样的变化，在我的磷酸酶。然而，磷酸酶的Vmax和K-m的强烈变化导致Vmax/K-m比的中度变化，与EGFR激酶活性的相应变化相当，但4 ℃时受体磷酸酶的变化除外。该模型表明，在4 degreesC下，EGF受体二聚化和去磷酸化的速率显著降低，这可能与膜脂质的相变有关。高分辨率的实验监测和分子水平的动力学建模相结合，使人们有可能定量占的温度依赖性的综合信号响应。
Stimulation of isolated hepatocytes with epidermal growth factor (EGF) causes rapid tyrosine phosphorylation of the EGF receptor (EGFR) and adapter/target proteins, which was monitored with 1 and 2 s resolution at 37, 20, and 4 degreesC. The temporal responses detected for multiple signaling proteins involve both transient and sustained phosphorylation patterns, which change dramatically at low temperatures. To account quantitatively for complex responses, we employed a mechanistic kinetic model of the EGFR pathway, formulated in molecular terms as cascades of protein interactions and phosphorylation and dephosphorylation reactions. Assuming differential temperature dependencies for different reaction groups, such as SH2 and PTB domain-mediated interactions, the EGFR kinase, and the phosphatases, good quantitative agreement was obtained between computer-simulated and measured responses. The kinetic model demonstrates that, for each protein-protein interaction, the dissociation rate constant. k(off) strongly decreases at low temperatures, whereas this decline may or may not be accompanied by a large decrease in the k(on) value. Temperature-induced changes in the maximal activities of the reactions catalyzed by the EGFR kinase were moderate, compared to such changes in the I of the phosphatases. However, strong changes in both the V-max and K-m for phosphatases resulted in moderate changes in the V-max/K-m ratio, comparable to the corresponding changes in EGFR kinase activity, with a single exception for the receptor phosphatase at 4 degreesC. The model suggests a significant decrease in the rates of the EGF receptor dimerization and its dephosphorylation at 4 degreesC, which can be related to the phase transition in the membrane lipids. A combination of high-resolution experimental monitoring and molecular level kinetic modeling made it possible to quantitatively account for the temperature dependence of the integrative signaling responses.